NutriDay Junior Promo

I bought a pack of NutriDay Junior because they were running a promo that stated that you would win guaranteed prizes. I followed the prompts to redeem my prize of an Acrobranch Adventure voucher. I have been communicating with them since the 4th of April and the matter hasn't been resolved. I gave them my contact number and email but no one has reverted back to me. I'm really disappointed with their lack of professionalism. My wife got her voucher without any hassles but we can't go to Acrobranch because we're waiting for the other voucher.